Philippine Merchant Marine School - Learning Resource Center

17/08/2026

WALANG PASOK!

Suspendido pa rin ang pasok sa lahat ng antas sa pampubliko at pribadong paaralan sa Lungsod ng Las Piñas BUKAS, August 18, 2026, Tuesday, dahil sa mga pag-ulan na dala ng habagat.

Pinapayuhan ang lahat na mag-ingat at manatiling nakaantabay sa mga opisyal na anunsyo mula sa ating lokal na pamahalaan.

05/08/2026

18/07/2026

☺️

⚓ LESSON 118: THE SIX SAILINGS EVERY DECK OFFICER MUST KNOW

Navigation is not just plotting positions—it is knowing which sailing method applies to a particular navigation problem.

Choosing the wrong method can lead to incorrect distances, courses, and voyage calculations.

Every Officer of the Watch should understand the six fundamental sailings and when to use them.

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🧭 1. PARALLEL SAILING

Used when:

✅ Both positions are on the same latitude
✅ Vessel proceeds East or West

Key Points:

• DLat = 0
• Distance = Departure
• DLo must be converted using latitude

Formula:

Departure = DLo × cos Latitude

📌 Think: Same Latitude = Parallel Sailing

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🧭 2. MERIDIAN SAILING

Used when:

✅ Both positions are on the same longitude
✅ Vessel proceeds North or South

Key Points:

• DLo = 0
• Distance = DLat
• 1 minute of latitude = 1 nautical mile

📌 Think: Same Longitude = Meridian Sailing

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🧭 3. PLANE (MIDDLE-LATITUDE) SAILING

Used when:

✅ Distance is relatively short
✅ Earth’s curvature can be neglected for practical calculations

Key Relationships:

• DLat = Distance × cos Course
• Departure = Distance × sin Course

When DLo is involved:

Departure = DLo × cos Mean Latitude

📌 Commonly used for routine navigation calculations.

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🧭 4. MERCATOR SAILING

Used when:

✅ Accurate Rhumb-Line solution is required
✅ Significant change in latitude exists

Uses:

• DLat
• DLo
• Meridional Parts (MP)
• Difference of Meridional Parts (DMP)

Formula:

tan Course = DLo ÷ DMP

📌 A rhumb line crosses all meridians at the same angle.

📌 Mercator Sailing is chosen because of the navigation problem—not simply because the voyage exceeds a certain distance.

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🌍 5. GREAT-CIRCLE SAILING

Used when:

✅ Finding the shortest distance between two positions on Earth

Advantages:

• Shortest route
• Saves time and fuel on long ocean passages

Important:

⚠️ Course continuously changes throughout the voyage.

Vertex Rule:

• Poleward initial course → Vertex ahead
• Equatorward initial course → Vertex astern

📌 Most transoceanic voyages benefit from Great Circle routing.

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🌍 6. COMPOSITE GREAT-CIRCLE SAILING

Used when:

✅ A limiting latitude must not be exceeded

Common Reasons:

• Ice limits
• Heavy weather
• Company route restrictions
• Seasonal navigation hazards

Route Structure:

1️⃣ Great Circle to limiting latitude

2️⃣ Parallel Sailing along limiting latitude

3️⃣ Great Circle to destination

📌 Combines safety with the efficiency of Great Circle routing.

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⚓ QUICK MEMORY GUIDE

🔹 Same Latitude → Parallel Sailing

🔹 Same Longitude → Meridian Sailing

🔹 Short Distance Problem → Plane Sailing

🔹 Accurate Rhumb Line → Mercator Sailing

🔹 Shortest Ocean Route → Great Circle Sailing

🔹 Limiting Latitude Required → Composite Great Circle Sailing

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🌊 Maritime Journey PH Reminder

A competent navigator does not merely solve calculations—he understands why a particular sailing method is used.

Knowing the correct sailing method is the foundation of accurate voyage planning and safe navigation.

17/07/2026

26/06/2026

📣 𝐀𝐫𝐞 𝐲𝐨𝐮 𝐫𝐞𝐚𝐝𝐲 𝐭𝐨 𝐛𝐞𝐠𝐢𝐧 𝐲𝐨𝐮𝐫 𝐞𝐱𝐜𝐢𝐭𝐢𝐧𝐠 𝐜𝐨𝐥𝐥𝐞𝐠𝐞 𝐣𝐨𝐮𝐫𝐧𝐞𝐲?

All incoming college freshmen are invited to attend the Freshmen Orientation for A.Y. 2026-2027. Get to know your campus, meet your professors and fellow students, and learn everything you need to start strong and succeed in college!

Don't miss this important event—your college experience starts here!

All Academic Programs
𝗝𝘂𝗻𝗲 𝟮𝟵, 𝟮𝟬𝟮𝟲 | 𝟵:𝟬𝟬-𝟭𝟭:𝟯𝟬 𝗔𝗠 @𝗣𝗠𝗠𝗦 𝗚𝘆𝗺

𝗔𝘁𝘁𝗶𝗿𝗲:
• Monday/𝗧𝘆𝗽𝗲 𝗔 𝗨𝗻𝗶𝗳𝗼𝗿𝗺 (𝘪𝘧 𝘢𝘷𝘢𝘪𝘭𝘢𝘣𝘭𝘦); or
• Minimum uniform requirement: 𝗪𝗵𝗶𝘁𝗲 𝘀𝗵𝗶𝗿𝘁 (𝘵𝘶𝘤𝘬𝘦𝘥 𝘪𝘯), 𝗯𝗹𝗮𝗰𝗸 𝗽𝗮𝗻𝘁𝘀, 𝗮𝗻𝗱 𝗯𝗹𝗮𝗰𝗸 𝘀𝗵𝗼𝗲𝘀.

Your attendance is highly encouraged as important information about your academic journey, student services, policies, and campus life will be discussed.

We look forward to welcoming you to the PMMS family. See you there!

See material below for details.

22/06/2026

Good News!
With or Without NaMMAT, anyone can enroll!

As per MARINA Advisory No. 2026-34

14/06/2026

PMMS SENIOR HIGH SCHOOL

Enrollment is still ongoing.
Still no top-up and P620 (one-time processing fee for Grade 11 only).

Visit PHILIPPINE MERCHANT MARINE SCHOOL Las Piñas Campus (Admission Office)

Office Hours: Monday to Saturday (08:00 am – 03:00 pm)

Bring the following requirements:
• Online Registration Form
• Copy of Report Card Grade 10
• Certificate of Good Moral Character
• Original copy of PSA Birth Certificate
• 4 pcs. 1x1, 1pc. 2x2 ID picture

Start your journey with us and be part of a community committed to excellence in education.

For inquiries, please contact:
(0968) 755-4081 (0922) 805-0245
(0962) 796-1841 (02) 8877-3300
San Antonio Valley Rd., Talon Uno Las Piñas City
[email protected] & [email protected]

14/06/2026

Ready to turn your passion into profit and be your own boss?

Enroll now and be part of our BS Entrepreneurship Program, and start bringing your business dreams to life! ✨📈

Entrance Exam Schedule: Mon-Sat 9am -3pm

**Hurry and enjoy 15% OFF on Tuition Fee (per unit) for all programs

14/06/2026

Ready to become the backbone of every successful organization?

Enroll now and be part of our BS Office Administration, and let's build the skills to organize, lead, and manage the corporate world.👩‍💼🌍✨

Entrance Exam Schedule: Mon-Sat 9am-3pm
**Hurry and enjoy 15% OFF on Tuition Fee (per unit) for all programs